The aim of this study is to examine the relationship between optical blur from poor refractive corrections (glasses) of workers using computers and their productivity and comfort in the workplace. We believe that improving the visual status of subjects who use computers will have a beneficial effect on productivity and visual comfort. All subjects will be required to complete a vision screening at no charge to decide if you qualify for the study. Subjects will select a frame to be worn during the period of the study. Subjects will wear either your best correction or your present prescription in the frame for a period of 1-month. This will be a double-blind study, which means that neither the subject nor your doctors will know which pair of glasses the subjects will be wearing during the parts of the study. Subjects will complete 4 hours of testing during the first period (4 weeks) then the lenses will be switched for the second period (4 weeks). During the testing, subjects will complete two tasks on a standard computer. Either the investigator or co-investigator will explain to you how to do these simple tasks. One of these tasks will involve looking at printed material and entering correct information into the computer. The other task involves finding and deleting apostrophes from a manuscript on the computer. All subjects will answer a short survey before and after these tasks to check on symptoms resulting from using the computer. Before and after each period, the subjects also will answer another survey to measure their visual functioning using these glasses.